That is not just a visualization exercise. A client might think so and that is fine, but it is much more. The person is creating her own reality. If we have her create what she wants internally then it is likely to manifest externally quite readily. If she acts as if her visualization is real she most certainly will manifest it.
Also, a great way of getting around the situation where the client says she can't do certain session actions, is to get her to pretend that she can. Little does she know that that is really the exact same thing.
F: "Find an incident where you felt X"
C: "I can't find any"
F: "If you could, what kind of incident would it be"
C: "There would be some people standing there I guess"
etc.
It is very useful to play as-if with the future. It puts a desirable future there that the person can move towards. It makes it more specific and more real.
F: "When you have learned to play the piano, how is it going to be, what will you see, what will you hear?"
Not only does it connect the client up with her desirable future, it can also give us useful information. One clever trick to have the person go to the future after she has solved her current problems and then look back and see how she did it. It actually works more often than not.